Shoring requirements depend on the depth of the excavation or trench and the soil type. Here's a breakdown:

• General Requirement: If a worker is in a trench more than 1.2 meters (approximately 4 feet) deep, you must protect them from cave-ins or sliding material 1, 4. This can be done by:
  • Sloping or benching the walls of the excavation 1, 16
  • Installing a temporary protective structure (shoring, bracing, or caging) 1, 4
  • A combination of both sloping and a protective structure [1]
• Specific Depths and Engineering Requirements:
  • For excavations or trenches 3 meters (approximately 10 feet) deep or less, the temporary protective structures must be of sufficient strength to prevent cave-ins [2].
  • For excavations more than 3 meters deep, the temporary protective structure must be designed, constructed, and installed according to the specifications of a professional engineer [2].
  • In Saskatchewan, for a trench more than 3 meters deep, a professional engineer must design and certify the temporary protective structure [1].
  • In Saskatchewan, for trenches deeper than 6 meters in Type 1, 2, or 3 soil, or deeper than 4 meters in Type 4 soil, a professional engineer must design and certify the temporary protective structure [1].
• Underground Shafts:
  • For underground shafts between 1.5 meters and 6 meters deep, the walls must be retained by temporary protective structures strong enough to prevent collapse [3].
  • For shafts 6 meters or more deep, the temporary protective structures must be certified by a professional engineer [3].

It's crucial to consider factors like soil type, nearby structures or traffic, and potential hazards like underground utilities when determining shoring needs 1, 2, 3.